The present invention relates to bulk containers, and in particular, flexible bulk containers having supporting vertical side beams which prevent bulging of the container when loaded with flowable materials.
To store and transport flowable materials such as grain, chemicals, fertilizers and minerals, intermediate or semi bulk shipping containers have been developed. These containers are often cylindrical in design and are formed from a flexible woven material. Approximately 1,000 to 3,000 lbs. or more of bulk material may be loaded within the containers which customarily have top loading and bottom discharge features. Flexible intermediate bulk containers are easily transported and stored in an exposed condition and can be readily stacked for high density storage or transportation.
U.S. Pat. No. 4,194,652 describes a flexible intermediate bulk shipping container. A woven container is provided which includes a bottom portion and an upstanding side portion. The side portion is formed from one or more panels sewn together at the vertical edges. The lower edge of the cylindrical side portion is sewn to the periphery of the bottom portion, which includes a discharge spout. A similar spout is situated at the top of the container to facilitate in the loading thereof.
As a result of the inherent properties of flowable or bulk material, a lateral force generated by the bulk material is exerted upon the side wall panels of flexible bulk containers. Flexible circular side walls tend to uniformly distribute the lateral force caused by the bulk material about the containers. However, the lateral force tends to cause a bulging of the container. Bulging is an undesired effect as it distorts the containers causing a loss of storage space when the containers are stacked together. In the extreme, bulging can cause rupture of the container and a spilling of the container""s contents. This is especially undesirable when the contents are chemical in composition.
Transportation, be it by truck, train or ship, subjects flexible containers to forces of momentum. Hence, acceleration or deceleration of the transporting vehicle may cause a shifting of the contents of the containers and of the container themselves. To ease some of the problems associated with transportation, flexible intermediate bulk containers have been developed with rigid supporting members.
U.S. Pat. No. 5,025,925 describes a flexible intermediate bulk container flexible container having support pillars associated therewith. The outer surface of the container has vertically placed channels which receive the support pillars. The bottom ends of the support pillars are connected to a wooden pallet. The patent describes that the pillars are useful in reducing strain placed upon the upper end of the forward support pillars and the lower end of the backward support pillars when transport velocity is reduced.
U.S. Pat. No. 4,019,635 describes a tubular cardboard or corrugated board bulk intermediate container which rests within a sleeve that is secured to a bottom pallet. The patent further describes that the relative movement of the container within the sleeve provides for the absorption of a large proportion of the impact energy resulting from transportation of the container.
Because flexible intermediate bulk containers are collapsible, attempts have been undertaken to create self standing side walls to ease in the filling of the container.
U.S. Pat. No. 4,903,859 describes a flexible intermediate bulk container which incorporates rigid panels into the side walls of the container. The patent describes that the rigid panels permit the container to stand alone when filled.
While employing some form of supporting structure, the aforementioned patents do not address or attempt to alleviate the problem of container bulging.
One attempt to overcome the problems associated with bulging involves the placement of flexible containers within a rigid outer cubical frame work structure. Examples of such applications are found in the following patents: U.S. Pat. Nos. 5,437,384; 4,834,255; 4,901,885; 4,927,037; 5,052,579; 5,071,025; 5,282,544; 5,289,937; and 5,407,090. However, this approach is burdensome, expensive and complicated as it requires the construction of an external supporting structure.
It is therefore an object of the present invention to overcome the drawbacks associated with bulging of flexible bulk containers under load. This object is achieved through the use of vertical side beams positioned about the side wall panel of the flexible bulk container.
The object of the present invention is achieved by providing a flexible bulk container having vertically placed rigid side beams positioned about the side wall panel of the container. The side beams are connected at the top and at the bottom of the container in such a manner that the side beams bear the lateral forces of the flowable materials being contained and transfer those forces vertically to the top and bottom of the container as well as horizontally to the side wall panel.
The rigid side beams may be formed in a variety of shapes and may be composed of numerous materials. However, the shape and composition of the rigid side beams should function to transfer force longitudinally with relatively little deflection. A preferred shape for the rigid side beams is a triangular or V shaped profile as the material to strength ratio makes this shape economically feasible. A 45 degree angle at the apex is preferred, with the apex preferably pointing towards the center of the container. A commercially available product known as xe2x80x9cangle boardxe2x80x9d or xe2x80x9cedge boardxe2x80x9d would be suitable for constructing the side beams. It has a V shaped profile and is made of paper fiber or plastic.
The side beams may be held in place by a variety of fastening mechanisms. The use of an adhesive to affix the side beams to the side wall panel of the container may be employed. Additionally, the side wall panel may contain sleeves or pockets which receive the side beams and hold them in position about the side wall panel. Laminating the side beams to the side wall panel is also possible. In an alternative embodiment of the invention in which the container has a rigid top and bottom panel, molded receptacles in the top and bottom panels may be provided to secure the ends of the side beams and position them vertically about the side wall panel.
The spacing and number of side beams is dependent on the characteristics of the flowable material that is to be contained. Ideally, the spacing and number of side beams should result in the container being relatively cubical in appearance with bends in the side wall panel occurring between side beams and at the corners of the container. This is often accomplished by using eight side beams paired into sets of two which are spaced equidistant from the other sets about the side wall panel. The side beams act to transfer the lateral bulge force to the areas in the side wall panel where the bends occur. More importantly, the side beams transfer the lateral bulge force away from the side wall panel to the top of the container. This is accomplished by connecting the top ends of the side beams at or near the top panel of the container.
The flexible bulk container of the present invention can be made inexpensively from standard bulk packaging material. When the container is empty, it is fully collapsible and therefore economical to ship. When the container is filled with flowable materials, it conforms to a relatively cubical shape essentially eliminating the problems associated with a xe2x80x9cbulgedxe2x80x9d container and provides a more efficient bulk shipping and storage container. Additionally, the flexible bulk container of the present invention has improved stacking capabilities when loaded as a result of more evenly distributed forces and the added strength of the side beams.
In the most preferred embodiment of this application, a flexible container consist of a top panel having four sides and an upstanding side wall forming four sides, with the upstanding side wall being attached to the top panel. The upstanding side wall panel has an inner portion and an outer portion. Also included is a bottom panel that is attached to the upstanding side wall panel. The top panel, upstanding side wall and bottom panel form a chamber containing a flowable material, with the material creating a force acting against the upstanding wall. Also included will be eight side posts disposed about the inner portion of the upstanding side wall providing an octagon resistance pattern to the force exerted by the flowable materials. The octagon resistance pattern effects an equal diversion of the lateral bulge force about the side wall panel by providing lateral support for the container to prevent bulging thereof when the chamber contains flowable materials. This embodiment may be used especially for use with flowable materials such as liquids. Of course, bulk materials may also be placed therein.
This embodiment will also consist of sleeve means for retaining the eight side posts in an upright position. The sleeve means comprises a series of pockets formed on each of the inner upstanding side walls and the eight side posts are inserted within these inner pockets. In one embodiment, the eight side posts are formed in sets of two, and the side posts are interconnected. When the container is filled, the top and bottom ends of the post contact the top and bottom panel thereby allowing the transfer of lateral force from the side beam to the top and bottom panel in the octagon resistance pattern.
The container may also include a bag disposed within the chamber, with the bag having the flowable materials disposed therein. In another embodiment, the top panel may contain an opening therein. Also, the sleeve means may comprise an upper band attaching an upper end of the side beam to the inner upstanding side wall and a lower band attaching a lower end of the side beam to the inner upstanding side wall.
An advantage of the present invention includes the transferring of the bulge force to the top and bottom panels to prevent bulging. Another advantage is the use of multiple side beams that are all interconnected. Yet another advantage is the use of individual side post that may be in a set of two, with the two side posts of the set being interconnected.
Another advantage is that the most preferred embodiment of this application is particularly suited for flowable materials such as liquids. Another advantage is the ability of the present invention to self right itself in the case where the container is jolted, jarred or moved. Yet another advantage is that the novel design provides resistance to toppling. Another advantage is the placement of the side post in the inner portion of the chamber.
A feature of the present invention is the employment of the octagon force resistance pattern. Another feature of the present invention is the placement of a pair of side beam members about each inner side wall, with the side beam members being properly spaced to provide for the octagon force resistance pattern.
Yet another feature of the invention includes connecting the top and bottom of the side beam members to each of the two adjacent side beam members. Still yet another feature is that the side beam members effect an equal diversion of the lateral bulge force about the side wall panel by providing lateral support for the container to prevent bulging thereof when the chamber contains the flowable materials. Another feature is the use of inner pockets which support the side beams in a substantially vertical position which in turn allows the diversion of the lateral bulge force.